Simon,

Simon South 写道：
> This also silences a configure warning about the "sphinx-build"
> command being unavailable.

./configure is a noisy boy; not every ‘warning’ warrants action. 
A GNU info manual is definitely nice to have though!

> +       ("makeinfo" ,texinfo)
>         ("pkg-config" ,pkg-config)
> -       ("ragel" ,ragel)))
> +       ("ragel" ,ragel)
> +       ("sphinx-build" ,python-sphinx)))

It's a subjective line but I'd prefer the labels match the package 
here.  Nitpick, can be fixed up in post.

Otherwise LGTM,

T G-R